After opening the season with six consecutive victories, Wheaton turned the ball over twice and gave up a touchdown on special teams in a 35-25 loss to North Central that cost the Thunder the College Conference of Illinois and Wisconsin title and caused them to take a long look in the mirror.

Truth be told, they didn’t like everything they saw.

“That was tough. It was really tough to lose that game,” said Mike Swider, who’s in his 21st season as the Wheaton head coach and 32nd year overall at the Illinois school. “Sometimes when you’re winning, you don’t pay attention to some of your deficiencies the way that you should, but a loss wakes you up.

“We said, ‘We have to change some things if we’re going to beat the big boys.’”

The 12th-ranked Thunder (11-1) haven’t lost since, atoning for the regular-season loss with last week’s 31-14 second-round playoff win over North Central to earn a date in the NCAA Division III quarterfinals against No. 2 Mary Hardin-Baylor (12-0) at noon Saturday at Crusader Stadium in Belton.

It is the third quarterfinal appearance for Wheaton, which seeks its second ever trip to the national semifinals.

Swider is a Wheaton lifer who has been at the helm for all of the Thunder’s quarterfinal trips. A Wheaton player in the late 1970s, he returned to his alma mater and has stayed long enough to coach his sons.

“I returned in 1985 at age 30 and just finished my 32nd year. When I came back, I didn’t think it would be forever, but Wheaton is a special place,” he said. “I’ve seen it through the lens of a player, a coach and a father.”

In his third decade as head coach at the school of about 2,500 students in a Chicago suburb, Swider has a team that has ridden its stout defense and efficient offense to the cusp of the semifinals.

The Thunder rank No. 2 in D-III against the run — giving up an average of just 56.9 yards rushing per game — 14th in total defense (264.1 yards) and 11th in points allowed (13.8). Swider believes the reason for his defense’s success is simple.

“Right now we’ve got some really good payers on that side of the ball,” he said. “We’re good on defense because we have good players.

“When you recruit good players, you look good.”

Among the leaders of the Thunder defense are senior linebacker and CCIW defensive player of the year Caleb Ashby and junior end Chase Greenlee — who have combined for 24 sacks — along with sophomore linebacker Eric Stevenson (team-leading 91 tackles) and junior nose tackle Noah Spielman, a Toledo transfer and son of former Ohio State star and NFL player Chris Spielman.

“(Ashby) is very versatile. We can put him at several places on the field,” Swider said. “(Greenlee) just plays hard. You can’t get that guy to slow down.”

That makes Greenlee the perfect fit for Wheaton, which builds its program based on maximum effort, according to Swider.

“I think we recruit high-character kids that stay around and keep playing no matter what,” he said. “It’s easy to keep playing when you’re in a war, but our kids play hard even when they’re up.

“I think glory is a bad motivator. Causes are a good motivator. You’ll only chase glory as long as you’re getting it. If you have a cause to believe in, you’ll keep going. Fighting for your teammate and for your school are reasons to keep playing hard.”